Program z1;
uses crt;
var
chyslo,a,b,c,d,k:integer;
t1,t2:text;
begin
clrscr;

assign(t1,'c:\count.in');
reset(t1);
read(t1,chyslo);
close(t1);

a:=(chyslo mod 10000 div 1000);
b:=(chyslo mod 1000 div 100);
c:=(chyslo mod 100 div 10);
d:=(chyslo mod 10 div 1);



if(a=b)or (a=c) or(a=d) then k:=1;
if(b=a)or (b=c) or(b=d) then k:=k+1;
if(c=a)or (c=b) or(c=d) then k:=k+1;
if(d=a)or (d=c) or(d=b) then k:=k+1;



assign(t2,'c:\count.out');
rewrite(t2);
write(t2,k);
close(t2);
         readln;
end.